MCA

Yes you can, if your backlogs extend your degree duration then it problematic otherwise if you cleared all the backlogs within standard degree duration then its fine

MCA course is specially designed for computer graduates and robotics is a part of mechanical , there is no course named as MCA in robotics, you can pursue BE Btech in robotics

MCA course is specially designed for computer graduates and robotics is a part of mechanical , there is no course named as MCA in robotics, you can pursue BE Btech in robotics

Without maths is difficult to go for BCA/ MCA but you may check with distance education universities.

AIMCET is an entrance test is conducted for MCA if someone wants to take admission in IIT's. Otherwise many other university doesn't need any entrance test to be passed.
Usually 50% marks is enough to take MBA admission.

Most of the colleges in Tamil Nadu discontinuing MCA. Duration is Three years and no specialisation. For this cost by saving two years of life and money you can do one year post graduation ceremony n UK which will make you employable. However you have to be particularly select a specialised area of study in it field